Biochar effects in the growing and control of biotic and abiotic stress in Astrophytum myriostigma and Astrophytum capricorne

Research goal: Based on the information found in the literature on biochar, its ability to improve the quality and yield of productions and to influence soil microflora. In this work, studies were carried out at different concentrations in pots to assess whether the addition of this material to the growing medium can influence the growth and control of biotic and abiotic stresses on Astrophytum myriostigma and Astrophytum capricorne.

Materials and Methods: The experiments, started in June 2020, were conducted in the greenhouses of CREA-OF in Pescia (PT), Tuscany, Italy (43°54′N 10°41′E). The experimental groups were: i) group control, irrigated with water and substrate previously fertilized; ii) group with biochar 5%, irrigated with water and substrate previously fertilized; iii) group with biochar 10%, irrigated with water and substrate previously fertilized; iv) group with biochar 15%, irrigated with water and substrate previously fertilized; On June 30, 2021, plant height and circumference, number and length of thorns, vegetative weight, root weight, number of fruits, fruit weight, number of flowers, flower life, plants dead from cold stress, plants dead from Rhizoctonia solani.

Results and Discussion: The test showed a significant increase in the agronomic parameters analyzed in biochar-treated plants on Astrophytum myriostigma and Astrophytum capricorne. The test also showed an improvement in plant quality in terms of increased number of thorns, fruits, flowers and increased resistance to cold stress and the pathogen Rhizoctonia solani. The trial also showed that an increase in substrate biochar content of 10%-15% improved plant growth performance compared to lower 5% contents.

Conclusions: The experimentation carried out at CREA-OF in Pescia showed how the application of biochar to the cultivation substrate of Astrophytum myriostigma and Astrophytum capricorne can significantly improve the quality and the resistance to biotic and abiotic stresses of the plants. As in other experiments in the literature, the application of this soil conditioner also resulted in positive effects in the control of pathogenic fungi, particularly Rhizoctonia solani. This effect was probably mediated by the presence of microorganisms in the biochar that, in addition to having an effect on plant stimulation, may have a fundamental role in their biocontrol activity of substrate pathogens. Interesting results have also been the increase in the number of thorns, flowers and fruit duration and resistance to cold stress in plants grown with biochar.